Separator blowoff valve



M 1950 F. A. DEXTER 2,508,015

SEPARATOR BLbwoFF VALVE Filed Sept. 12, 1946 I NVENTOR If eaerlo/t A De wife/ Patented May 16, 1950 UNITED STATES SEPARATOR BLOWOFF'VALVE Frederick: A. Dexter, 0range, Mass., .assignoreto The Leavitt Machine Company, p0range,Mass., a corporation of Massachusetts Application September 12,1946; SerialNo. 696,434

3 Claims. (01. 210-166) This invention relates to blow-ofi valves, and

-more particularly to blow-off valves -used as an adjunct to separators provided in compressed air systems for the purpose of removing moisture, oil and dirt fromthe system.

(me of the objects of the invention is to provide a blow-off valve implemented with a compression spring and'designe'd to be held against its seat by the compressed air of the system at normal working pressures. The valve, its said spring and associated parts-are so designed and proportioned that when the system drops below a predetermined pressuretermed the blow-01f pressure,

the spring will lift the valve off its seat and'present the relatively large opening of the valve through which the accumulated moisture, oil and dirt will be blown (by the. pressure in the system) to the atmosphere. The improved blow-01f valve is provided with a member which projects outside the valve and by which the valve may be manually raised oil itsseat when it is desired to cause a blow-off at any time and irrespective of the system pressure and at pressures above those Which eifect an automatic blow-oil. The

improved blow-off valve is furtherprovided with a relatively small passage leading to atmosphere presenting a constant ven for the accumulated moisture and oil which are thus continuously being eliminated from the system. The aforementionedsprovision for automatic blow-off and I for manual blow-off functions to rid the valve of moisture, oil and dirt which may have accumulated therein despite the aforesaid constant vent and to "flush outthe valve including the constant vent passages.

A further object-0f the invention is'to provide ablow-ofi of the character described which will be comprised of a smallnumber of partswhich are of simple construction and economical to manufacture.

A still further object of the invention is to provide a blow-off valve'of the character described which will be reliable in operation'and will effectively rid the system of accumulated moisture,

oil and dirt both during the constant venting'and its periodic blow-off.

A further object is toprovide a blow-off valve having a minimum of communicating internal passages of simple'construction which present a wide clearance space for the moisture, oil and dirt,

with no obstructions and restrictions to their easy flow through the valve.

' For the attainment of the foregoing and such other objects as may-appear or be pointed out,

{1 have shownan embodiment of my invention in 1 the'accompanying drawing; wherein:

Fig. 1 isa sectional elevation of .a separator showing the application of the improved blow-101T valve and Fig. 2 is a sectionalzelevation of the improved blow-off valve, onenlarged scale.

The improved blow-61f valve issshown in operative relation to a particular "type of separator which is placed in iaoompressed air system for the purpose of separatingmoisture, oil and .dirt

from the compressed: air in theisystem; the function of theiblow-o'ff valve being to eliminate the moisture, oil and dirt accumulated in the separator and-todischarge the same to atmosphere. It will be understood, however,'-that the improved blow-off valve maybe .used with other types of separators, that it may be used forany-kind vof vfluid system, steam, gas as well as compressed .air, and :that the improved blow-oil valve may be applied .to the piping, valves, fittings, chambers and other partsof the fluid system and is notlimited in itsuseas an adjunct toseparators.

Separator i0 is connected, at inlet ll andoutlet -I9, in the compressed air system, the compressed air passing throughinlet passage 12 into a large centralspace l-3within ashell I4 which is .closed'at the top exceptfor thesaid inlet Hand which has an open mouth l5'at its bottom end. :The compressed airexpands upon entering large space 13 of the shell-M- andmoves downwardly and through open mouth liof the shell and then upwardly through thelannular space It between shell l4;--and.cylind ricalcasing-l1 of the separator, and back into the =main' line of the compression system through the outlet passage I8. At the lower end of cylindrical casing I1 is secured-in any preferred or desired manner as by bolts and suitable gaskets, as shown, a casing '28 which has an upper percipitation space 2| stream gravitates, and is forced by the pressure of the system, through passage 22'into separation chamber 23. 'Valve block "30 hasa large central "cavity 3| 'opening-at 'the'top of the block in a mouth 35- which is of -somewhat larger diameter vrnosphere. is for the most part-i. e., at the annular space than the diameter of cavity 3| to provide an annular shoulder 36. Within the enlarged mouth 35 is press fitted a cylindrical strainer which is fabricated of wire mesh to form a cylindrical wall 25 and a closed upper end 21; the lower end of wire mesh strainer 25 is left open. This open end or bottom of the strainer rests on a disc 26 of any preferred or desired material such as metal which seats on annular shoulder 36 of valve block 33 and which is likewise press fitted in mouth 35.

Central cavity 3| of valve block 30 terminates at its lower end in an annular, tapered surface 32 which is concentric to a central, cylindrical bore 33 of reduced diameter which extends from central cavity 3| to and through the lower end of the valve block. Near its lower opening, bore 33 has a reduced portion 37 which provides an annular shoulder 38. Within the central cavity 3| is a valve 4| having an annular tapered surface 42 which engages similar tapered seat 32 of the valve block. Valve 4i is formed integrally with a stem 4'! which is slidable in reduced portion 3'! of the central bore, the end of the stem extending beyond valve block 38-. Within the annular space between valve stem 41 and central bore 33 is a coil compression spring 8, the lower end of which seats on annular shoulder 38 of the central bore. Between the annular tapered surface 52 of the valve 4| and its juncture to valve stem 41 is an annular shoulder 48 on which the upper end of spring 8 seats.

Opening into central bore 33 near the lower end of the valve block is an outlet 39 which is internally threaded to receive a nipple or fitting (not shown).

The disc 23 of strainer 25 has a plurality of holes 28 affording communication between the interior of the strainer and central cavity 3| of the valve blocks Strainer 25, Fig. 1, prevents large particles of dirt from entering the blow-off valve. The compressed air of the system and moisture, oil and smaller dirt particles separated from the system and isolated in separation chamber 23, however, pass through strainer 25 and holes 28 of disc 25 and enter central cavity 3|. Coil spring 8 and the fiat surface 43 of valve 4| are so designed that at the normal working pressure of the system, the pressure of the compressed air within the central cavity 3| overcomes the upward compressive force of spring 8 and maintains annular surface :22 of the valve tight on valve seat 32. When the pressure of the system is lowered to or below the blow-off pressure, compression spring 3 overcomes the downward force exerted by the compressed air upon the flat surface 43 of the valve and causes the valve to be lifted off its seat. There is thus provided a wide annular passage between tapered surface 32 of .the valve and valve seat 32, which passage opens into the annular space between valve stem 41 and .central bore 33; as already described, the annular ,space is open to atmosphere throughout outlet The improved blow-off valve thus provides a wide passage directly from central cavity 3| to at- It should be noted that this passage Moreover, both annular spaces are defined by outer walls, namely, valve seat 32 and central bore 33, which are continuous, in the longitudinal direction, with the walls of central cavity 3|. The moisture, dirt and oil accumulated in separation chamber 23, in strainer 25 and central cavity 3|, are blown to atmosphere through the aforedescribed wide passage; and at the same time, the wide passage itself is cleared of moisture, dirt and oil by the blast of compressed air therethrough. This blowoff occurs automatically when, as described above, the system pressure falls below a predetermined pressure. The improved valve may be caused to blow ofi at any time, irrespective of the system pressure, by forcing valve stem 4'. upwardly to raise its valve 4| off valve seat 32.

The improved blow-oil valve has a constant vent to atmosphere through which the moisture, oil and dirt is constantly discharged to atmosphere, by the system pressure. This constant vent is so small that there is no appreciable drop in pressure and a negligible loss of compressed air. To provide this constant vent, valve stem 41 has a small channel or drill hole 65 near its juncture to valve 4: diametrically disposed and opening at both ends into the annular space between valve stem 4'? and central bore 33. Centrally located in valve 4| is a small channel or drill hole 4 longitudinally extending from top surface 43 of the valve to the aioredescribed diametrical channel 45. Moisture, oil and dirt are thus constantly vented through channels 44 and 45 to the annular space of central bore 33 and through outlet 39 to atmosphere. Depending from disc 26, centrally located therein, is a pin 23 which enters the central vent channel 44 of valve 4| when the valve is raised during the blowofi, for the purpose of clearing the channel, which may have become clogged because of its relatively small diameter.

It will be observed that the blow-ofi valve herein disclosed is made of relatively few parts which can be quickly and readily assembled and disassembled fo cleaning or replacement. The assembly operation requires merely placement successively of spring 8, valve 41, disc 26 and strainer 25. Disassembling requires merely a reversal of these assembly steps.

I claim:

1. A blow-01f valve for a fluid system comprising a casing having an inlet and an outlet, a block secured to said casing and having means for securing it at a low point in said system and a central cavity opening at its upper end in an en larged mouth to provide an annular shoulder, an apertured disc press fitted in said enlarged mouth and seated on said annular shoulder, a cylindrical strainer having an open end press fitted in said mouth with its open end abutting the said disc, said central cavity terminating at its lower end in an annular tapered surface, a central bore extending from the lower edge of the said annular tapered surface of the central cavity and having at its lower end a portion reduced to present an annular shoulder, a valve having a stem and an enlarged head, said stem being slidable in said reduced portion of the central bore with its end extending beyond the said block, said valve head having a fiat upper surface and an annular tapered surface contacting th said annular tapered surface of the central cavity with the lower edges of the two tapered surfaces coextensive, the juncture of said stem and enlarged head presenting an annular shoulder equal in width to the said annular shoulder of the central between the said valve stem and central bore with its lower end seated on the annular shoulder of the central bore and with its upper end seated on the annular shoulder of the valve, an outlet at the lower end of said annular space leading to atmosphere, a diametrically disposed channel through the stem near its juncture to the valve head and opening into said annular space, and a central channel in the said valve head extending from its fiat upper surface to the said diametrically disposed channel, the said disc having a centrally located pin depending therefrom and receivable in the said central channel of the valve head when the valve is raised.

2. A blow-off valve for a fluid system comprising a casing having an inlet and an outlet, a block secured to said casing and having a threaded neck for securement at a low point in said system and a central cavity opening at its upper end in an enlarged mouth to provide an annular shoulder, an apertured disc press fitted in said mouth and seated on said annular shoulder, a cylindrical strainer having an open end press fitted in said mouth with its open end abutting the said disc, said central cavity terminating at its lower end in an annular tapered surface, a central bore extending from the lower edge of the said annular tapered surface of the central cavity and having at its lower end a portion reduced to present an annular shoulder, a valve having a stem and an enlarged head, said stem being slidable in said reduced portion of the central bore with its end extending beyond the said block, said valve head having a flat upper surface and an annular tapered surface contacting the said annular tapered surface of the central cavity with the lower edges of the two tapered surfaces coextensive, the juncture of said stem and enlarged head presenting an annular shoulder equal in width to the said annular shoulder of the central bore, a coil spring received in the annular space between the said valve stem and central bore with its lower end seated on the annular shoulder of the central bore and with its upper end seated on the annular shoulder of the valve, said valve head being further provided with a central channel, an outlet at the lower end of said annular space leading to atmosphere, a constant vent affording communi- 6 cation between the atmosphere and said central channel in said valve head, the said disc having a centrally located pin depending therefrom and receivable in the said central channel of the valve head when the valve is raised.

3. A blow-off valve comprising a casing having an inlet and an outlet, a block secured to said casing and having an interconimunicating central cavity and central bore forming a valve seat at their juncture, the central cavity opening into an enlarged mouth to present an annular shoulder, an apertured disc in said annular shoulder, a cylindrical strainer in said enlarged mouth abutting said disc, a valve having a stem in said central bore and an enlarged head in said central cavity in closing engagement with said valve seat, a coil spring in the annular space between said valve stem and central bore, an outlet at the lower end of said annular space leading to atmosphere, a passage in said valve affording communication between the central cavity and said annular space, said passage including a central, vertical channel in said valve head, the said disc having a central depending pin enterable in said channel when the valve is raised.

FREDERICK A. DEXTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 123,098 G-oodale Jan. 30, 1872 569,943 Shirely Oct. 20, 1896 820,146 Simonds May 8, 1906 848,079 Weiss Mar. 26, 1907 920,716 Beckman May 4, 1909 934,286 Cole Sept. 14, 1909 1,091,463 Vincent Mar. 24, 1914 1,207,593 Miller Dec. 5, 1916 1,247,533 Heath Nov. 20, 1917 1,314,566 Bogda Sept. 2, 1919 1,764,181 Raetz June 17, 1930 1,847,964 Hull Mar. 1, 1932 1,959,314 Wile May 15, 1934 2,074,245 Williamson Mar, 16, 1937 2,165,649 Parsons July 11, 1939 2,376,124 Coulbourn May 15, 1945 

